[PATCH 1/2] mmc: Add a new callback function to perform the 74 clocks cycle sequence

[Mathieu Othacehe]

From: Jean-Jacques Hiblot <jjhib...@ti.com>

Add a new callback function *send_init_stream* which start a sequence of
at least 74 clock cycles.
The mmc core uses *mmc_send_init_stream* in order to invoke the callback
function. This will be used during power cycle where the specification
requires such a sequence after power up.

Signed-off-by: Jean-Jacques Hiblot <jjhib...@ti.com>
---
 drivers/mmc/mmc-uclass.c | 13 +++++++++++++
 drivers/mmc/mmc.c        |  6 ++++++
 include/mmc.h            |  9 +++++++++
 3 files changed, 28 insertions(+)

diff --git a/drivers/mmc/mmc-uclass.c b/drivers/mmc/mmc-uclass.c
index c8db4f811c2..ca5bf1d11e6 100644
--- a/drivers/mmc/mmc-uclass.c
+++ b/drivers/mmc/mmc-uclass.c
@@ -83,6 +83,19 @@ int mmc_wait_dat0(struct mmc *mmc, int state, int timeout_us)
        return dm_mmc_wait_dat0(mmc->dev, state, timeout_us);
 }
 
+void dm_mmc_send_init_stream(struct udevice *dev)
+{
+       struct dm_mmc_ops *ops = mmc_get_ops(dev);
+
+       if (ops->send_init_stream)
+               ops->send_init_stream(dev);
+}
+
+void mmc_send_init_stream(struct mmc *mmc)
+{
+       dm_mmc_send_init_stream(mmc->dev);
+}
+
 static int dm_mmc_get_wp(struct udevice *dev)
 {
        struct dm_mmc_ops *ops = mmc_get_ops(dev);
diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
index 31a72366206..086826c668c 100644
--- a/drivers/mmc/mmc.c
+++ b/drivers/mmc/mmc.c
@@ -1663,6 +1663,10 @@ static int mmc_execute_tuning(struct mmc *mmc, uint 
opcode)
 }
 #endif
 
+static void mmc_send_init_stream(struct mmc *mmc)
+{
+}
+
 static int mmc_set_ios(struct mmc *mmc)
 {
        int ret = 0;
@@ -2929,6 +2933,8 @@ int mmc_get_op_cond(struct mmc *mmc, bool quiet)
 retry:
        mmc_set_initial_state(mmc);
 
+       mmc_send_init_stream(mmc);
+
        /* Reset the Card */
        err = mmc_go_idle(mmc);
 
diff --git a/include/mmc.h b/include/mmc.h
index 81bccb4cf12..c2d275cdc3e 100644
--- a/include/mmc.h
+++ b/include/mmc.h
@@ -487,6 +487,14 @@ struct dm_mmc_ops {
         */
        int (*set_ios)(struct udevice *dev);
 
+       /**
+        * send_init_stream() - send the initialization stream: 74 clock cycles
+        * This is used after power up before sending the first command
+        *
+        * @dev:        Device to update
+        */
+       void (*send_init_stream)(struct udevice *dev);
+
        /**
         * get_cd() - See whether a card is present
         *
@@ -566,6 +574,7 @@ struct dm_mmc_ops {
 
 /* Transition functions for compatibility */
 int mmc_set_ios(struct mmc *mmc);
+void mmc_send_init_stream(struct mmc *mmc);
 int mmc_getcd(struct mmc *mmc);
 int mmc_getwp(struct mmc *mmc);
 int mmc_execute_tuning(struct mmc *mmc, uint opcode);
-- 
2.47.1